Belted absorbent article

ABSTRACT

A belted absorbent article ( 10 ) having an absorbent structure ( 16 ) and a pair of opposed belt halves ( 12, 14 ) attached to the absorbent structure ( 16 ) via a respective joint ( 50 ). The joint ( 50 ) between each belt half ( 12, 14 ) and the absorbent structure ( 16 ) is designed such that when each belt half is subjected to a tension force of 35 N acting along the belt half and the direction of applied tension creates an angle (α) to the transverse axis (T) of the absorbent structure, the following minimum average release times (t) of each belt half from the absorbent structure are attained:  
     when α=10°, t&gt;&gt;720 seconds;  
     when α=20°, t&gt;&gt;330 seconds;  
     when α=25°, t&gt;&gt;240 seconds;  
     when α=30°, t&gt;&gt;180 seconds; and  
     when α=40°, t&gt;&gt;75 seconds.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the priority of Swedish PatentApplication No. SE 0002660-9, filed in Sweden on Jul. 13, 2000, andclaims the benefit of U.S. Provisional Application No. 60/218,050, filedin the United States on Jul. 13, 2000. The contents of Swedish PatentApplication No. SE 0002660-9 and U.S. Provisional Application No.60/218,050 are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Technical Field

[0003] The present invention relates to a belted absorbent article inthe form of a diaper, an adult incontinence garment, and the like,comprising an absorbent structure and a pair of opposed belt halvesattached to the absorbent structure at an end region thereof.

[0004] 2. Discussion of Related Art

[0005] Conventional diapers for young children generally comprise anabsorbent structure made up of an absorbent core sandwiched between aliquid pervious topsheet and a liquid-impervious backsheet. Theabsorbent structure has a front panel generally covering the child'sabdomen when worn and a rear panel generally covering the child'sbuttocks. The front and rear panels terminate in front and rear endregions respectively. In order to secure the diaper about the child, thefront and rear end regions are provided with cooperating fasteningmeans, for example in the form of a hook-and-loop fastening system or,alternatively, an adhesive tape tab system on the rear end regioncooperating with a landing zone on the front end region. To fit thediaper to the child, the child is normally laid down on his/her back,the diaper is inserted under the child such that the rear panel coversthe child's buttocks, the front panel is drawn between the child's legsto cover the abdomen and the fastening system is employed to join thelongitudinal sides of the respective front and rear end regionstogether.

[0006] Since it is almost exclusively a guardian who changes a child'sdiaper, the above-described method of securing a diaper to a child isgenerally fully satisfactory. However, particularly for incontinentadults who are capable of changing their own diapers, such a method ofsecuring an absorbent article about the body is inconvenient, primarilybecause the act of securing the absorbent article about the adult bodyis conducted when standing. Thus, it is awkward for the wearer tosimultaneously hold the absorbent article to the body in its correctorientation whilst fastening the front and rear end regions to eachother.

[0007] To at least partially alleviate the above-mentionedinconvenience, belted absorbent articles have been proposed. Forexample, a belted absorbent article is disclosed in FR-A-2 586 558 inwhich a one-piece belt is attached to the backsheet of an absorbentstructure. The article is secured about the wearer by bringing thearticle to the rear of the wearer to thereby cover the buttocks,fastening the belt about the waist of the wearer and then drawing thefront end region of the absorbent structure between the legs of thewearer and attaching the front end region to fastening means on thebelt.

[0008] EP-B-0 729 329 discloses a belted absorbent article in which,rather than using a single belt attached to the absorbent structure, twobelt halves are employed, with each belt half extending from arespective longitudinal edge of the absorbent structure. An advantage ofthis construction over that disclosed in FR-A-2 586 558 is that lessbelt material is needed. However, because two belt halves are employed,the joint between each belt half and the absorbent structure must becapable of withstanding the tension forces to which the belt halves aretypically subjected during use.

[0009] Particularly in terms of adult incontinence diapers, the size ofwearers varies greatly. In order to rationalize production and storageas much as possible, it is preferable to have as few product sizevariations as possible. This implies, on the other hand, that eachproduct size must be capable of fitting wearers of widely divergingshape and size. As a consequence, the forces to which the belt halvesare subjected during use will be, at least to a certain extent,dependent on the size of the wearer. To keep manufacturing costs low, itis of course advantageous to use as little material as possible.Nevertheless, a product must be sufficiently strong to fulfil itsintended purpose.

[0010] As is apparent from FIG. 1, when a belted absorbent article 10 issecured to a wearer, an angle a is created between, in effect, thelongitudinal axis L of the belt half and the transverse axis T of theabsorbent structure (it being assumed in the illustrated embodiment thatthe longitudinal edge of the belt half is parallel to the longitudinalaxis of the belt half). Depending on the size of the wearer in relationto the size of the article, the value of a will vary. The greater thesize of wearer, the greater the value of a will be. As the angle aincreases, an increasing shear force is applied to the joint between thebelt half and the absorbent structure.

[0011] The present applicant has discovered that, in order for a beltedabsorbent article to function satisfactorily, while still keepingmanufacturing costs as low as reasonably possible, the joint betweeneach belt half and the absorbent structure should preferably meetcertain minimum requirements depending on the angle a.

OBJECTS AND SUMMARY

[0012] It is therefore an object of the present invention to provide abelted absorbent article which functions satisfactorily while stillkeeping manufacturing costs as low as reasonably possible.

[0013] This object is achieved by means of the belted absorbent articlecomprising an absorbent structure extending about a first longitudinalaxis, the absorbent structure including a topsheet, a backsheet and anabsorbent batt disposed between the topsheet and the backsheet, theabsorbent structure having a transverse axis dividing the absorbentstructure into a front panel terminating in a front end region and arear panel terminating in a rear end region, the absorbent structurebeing delimited by opposed longitudinal edges and opposed transverseedges, and a pair of opposed belt halves attached to the absorbentstructure at the rear end region of the rear panel by a respectivejoint, each belt half extending about a second longitudinal axis suchthat each belt half extends outwardly from a respective longitudinaledge of the absorbent structure. The joint between each belt half andthe absorbent structure is designed such that when each belt half issubjected to a tension force of 35 N acting along the secondlongitudinal axis and the second longitudinal axis creates an angle a tosaid transverse axis of said absorbent structure, the following minimumaverage release times (t) of each said belt half from said absorbentstructure are attained:

[0014] when α=10°, t>>720 seconds;

[0015] when α=20°, t>>330 seconds;

[0016] when α=25°, t>>240 seconds;

[0017] when α=30°, t>>180 seconds; and

[0018] when α=40°, t>>75 seconds.

[0019] In a preferred embodiment of the invention, the following minimumaverage release times (t) of each belt half from the absorbent structureare attained:

[0020] when α=10°, t>>740 seconds;

[0021] when α=20°, t>>340 seconds;

[0022] when α=25°, t>>245 seconds;

[0023] when α=30°, t>>190 seconds; and

[0024] when α=40°, t>>80 seconds.

[0025] In a more preferred embodiment of the invention, the followingminimum average release times (t) of each belt half from the absorbentstructure are attained:

[0026] when α=10°, t>>760 seconds;

[0027] when α=20°, t>>350 seconds;

[0028] when α=25°, t>>250 seconds;

[0029] when α=30°, t>>200 seconds; and

[0030] when α=40°, t>>85 seconds.

[0031] In a further embodiment of the invention, the following minimumaverage release times (t) of each belt half from the absorbent structureare attained:

[0032] when α=10°, t>>780 seconds;

[0033] when α=20°, t>>360 seconds;

[0034] when α=25°, t>>255 seconds;

[0035] when α=30°, t>>210 seconds; and

[0036] when α=40°, t>>90 seconds.

[0037] In accordance with a most preferred embodiment of the invention,the following minimum average release times (t) of each belt half fromthe absorbent structure are attained:

[0038] when α=10°, t>>800 seconds;

[0039] when α=20°, t>>370 seconds;

[0040] when α=25°, t>>260 seconds;

[0041] when α=30°, t>>220 seconds; and

[0042] when α=40°, t>>100 seconds.

[0043] Thus, in accordance with the invention, by ensuring that thejoint between each belt half and the absorbent structure can withstand aforce of 35 N at predetermined values of the angle α for a minimumaverage release time per chosen angle, it has been found in practicethat failure of the belted absorbent article due to loosening of thebelt halves does not occur, at least not during normal use.

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The invention will be described in the following in greaterdetail by way of example only and with reference to the attacheddrawings, in which:

[0045]FIG. 1 is a schematic side view of a belted absorbent articlesecured to a wearer;

[0046]FIG. 2 is a schematic plan view of a belted absorbent articleaccording to the present invention;

[0047]FIG. 3 is an enlarged view of the joint between a belt half andthe absorbent structure of the belted absorbent article according to thepresent invention;

[0048]FIG. 4 is a schematic view of a cut out section of the articleaccording to the present invention being subjected to a test procedure;

[0049]FIG. 5 is a schematic plan view illustrating sections of thebelted absorbent article according to the present invention which are tobe cut out and tested;

[0050]FIG. 6 is a schematic elevational view of a test rig forsubjecting cut out sections of the belted absorbent product to a testprocedure;

[0051]FIG. 7 is an engineering drawing in the form of an elevationalview of one component of the test rig of FIG. 6;

[0052]FIG. 8 is an engineering drawing in the form of an end view of thecomponent of FIG. 7;

[0053]FIG. 9 is an enlarged view of a portion of the component of FIG.8;

[0054]FIG. 10 is an engineering drawing in the form of an elevationalview of a second component of the test rig of FIG. 6;

[0055]FIG. 11 is an engineering drawing in the form of an end view ofthe component of FIG. 10;

[0056]FIG. 12 is an enlarged view of a portion of the component of FIG.11;

[0057]FIG. 13 is an engineering drawing in the form of an elevationalview of a third component of the test rig of FIG. 6; and

[0058]FIG. 14 is an engineering drawing in the form of an end view ofthe component of FIG. 13.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0059] In the drawings, reference numeral 10 generally denotes a beltedabsorbent article according to the present invention. The expression“belted” implies that the article is provided with means which passaround at least a portion of the waist of a wearer when worn and whichmeans meet to thereby secure the article around the waist of the wearer.In the present invention, these means are belt halves 12, 14.Preferably, the invention is to be practised on a disposable article. Inthis respect, the term “disposable” means any article which is notintended to be laundered and which is normally discarded once removedfrom the wearer.

[0060] In addition to the belt halves 12, 14, the belted absorbentarticle further comprises an absorbent structure 16 extending about afirst longitudinal axis 18. Thus, when the article is being worn, thefirst longitudinal axis will generally bisect the wearer into a lefthand side and a right hand side when viewed from above. The absorbentstructure 16 includes a topsheet 20, a backsheet 22 and an absorbentbatt 24 disposed between the topsheet and the backsheet. The specificcomponents used to form the absorbent structure may be any of the typescommonly used for such purposes. For example, a suitable topsheet 20 maybe any soft flexible non-irritating liquid permeable material, such aswoven or nonwoven webs of natural fibres (e.g. wood or cotton fibres),synthetic fibres (e.g. polyester or polypropylene fibres or coformfibres), combinations of natural and synthetic fibres, apertured filmsor porous foams. Preferably, the topsheet 20 is manufactured from anonwoven spunbonded polypropylene material having a basis weight of lessthan 20 g/m². Nevertheless, when the topsheet comprises a nonwoven web,the nonwoven web may instead be carded, wet-laid, meltblown, hydroformedor hydroentangled. The backsheet 22 is impervious to liquids and ispreferably manufactured from a thin plastic film such as polyethylene,polypropylene, polyvinyl-chloride, or the like, or composite materialssuch as a film coated nonwoven material. The absorbent core 24 may bemade in widely varying sizes and shapes and may comprise any suitablewettable hydrophilic fibres such as cellulosic fibres, possibly blendedwith synthetic polyolefin fibres. In certain embodiments, the absorbentcore 24 may comprise a mixture of superabsorbent hydrogel-formingparticles mixed with the hydrophilic fibres.

[0061] The topsheet 20 and the backsheet 22 are connected together,either directly or indirectly, using any suitable known means. Forexample, the topsheet and the backsheet can be affixed directly to eachother in selected areas using continuous or patterned layers ofadhesive. The adhesive layer or layers may be sprayed or extruded inlines or dots.

[0062] As is most clearly apparent from FIG. 2, the absorbent structurehas a transverse axis T dividing the structure into a front panel 26terminating in a front end region 28 and a rear panel 30 terminating ina rear end region 32. The absorbent structure is delimited by opposedlongitudinal edges 34 and opposed transverse edges 36. Projecting fromits opposed longitudinal edges 34, the front end region 28 displaysfastening tabs 38. In a manner which will be explained in greater detailbelow, the fastening tabs 38 form part of a fastening system and arearranged to cooperate with corresponding parts of the fastening systemon the belt halves 12, 14. Although the fastening tabs 38 are shownprojecting from the longitudinal edges 34 of the front panel of theabsorbent structure 16, it is to be understood that the tabs may insteadproject from the transverse edge 36. In a further alternativeembodiment, the fastening tabs 38 may be in the form of one or morepatches affixed to the topsheet 20 on the front panel 26.

[0063] Each belt half extends about a respective longitudinal axis(hereinafter referred to as the second longitudinal axis) 40, 42, withthe belt halves being joined to the absorbent structure 16 such that thetwo belt halves 12, 14 extend generally perpendicularly with respect tothe first longitudinal axis 18 of the absorbent structure 16.Accordingly, in the shown embodiment, the two belt halves 12, 14 extendgenerally perpendicularly from the longitudinal edges 34 at the rear endregion 32 of the rear panel 30 of the absorbent structure 16. It is,however, to be understood that the belt halves may be manufactured suchthat they form an angle to either the first longitudinal axis 18 or tothe longitudinal edges 34. The belt halves may be made of any suitablematerial or material combinations. In an exemplary embodiment, the belthalves are made from a laminate of an embossed transparent polypropylenefilm and a thermobonded nonwoven web of 30 g/m² basis weight. Forimproved wearer comfort, the belt halves are attached to the absorbentstructure such that, when worn, the nonwoven web faces the wearer. Inanother embodiment, the belt halves may be made exclusively of nonwovenmaterial. Depending on the intended size of the wearer, each belt half12, 14 has a transverse extension of typically 10 to 12 cm and alongitudinal extension (i.e. the extension beyond the longitudinal edge34 of the absorbent structure) of, for example, 35 cm. The belt halvesare preferably identical, though it is to be understood that theabsorbent article of the present invention may also have belt halves ordifferent length and/or width.

[0064] The inside surface, i.e. that surface of the belt half facing thewearer when worn, of one belt half (belt half 14 in FIG. 2) is providedwith a first fastening means 44 for releasable engagement with acomplementary second fastening means 46 on the outer surface of theother belt half 12 to thereby allow the belt to be secured around thewaist of the wearer. The actual type of belt fastening means may be anyof those known in the art, for example a hook-and loop system, anadhesive system, a system of buttons and button-holes, etc. Irrespectiveof the type of fastening system employed, the fastening system should becapable of allowing adjustment of the tension of the belt halves aroundthe waist of the wearer. Thus, in the embodiment shown on FIG. 2, thefirst fastening means is a patch of hook material while the secondfastening means is a strip of loop material extending over a significantlength of the belt half 12. It will of course be apparent to the skilledperson that more than one patch of hook material may be used and thatthe strip of loop material may be a plurality of smaller patches of loopmaterial.

[0065] The surface of the belt halves remote from the wearer when worn,i.e., the outer surface of the belt halves, is provided with means (notshown) forming a part of the fastening system of the absorbent article.The means on the belt halves is complementary to, and thereforedependent on, the type of fastening tab 38 employed in the front endregion 28 of the front panel 26. Thus, if the fastening tabs 38 areadhesive tabs, at least a region of the outer surface of the belt halves12, 14 should be capable of releasable engagement of the adhesive tabs.In the case in which the outer surface of the belt halves is a plasticsfilm, it is advantageous to provide a reinforced so-called landing zoneor zones for the tabs to engage with. If the fastening tabs 38 are hooktabs of a hook-and-loop fastening system, the outer surface of the belthalves will be provided with, or made from, a loop material forengagement with the hook fastening tabs. Another possibility is that theouter surface of the belt halves is provided with patches of hookmaterial for engagement with loop material of the topsheet 20 or patchesof loop material attached to the topsheet in the front end region 28 ofthe front panel 26.

[0066] In a manner known per se in the art, the absorbent article of thepresent invention may be provided with elasticated leg cuffs to therebyprovide improved sealing of the article around the legs of the wearerwhen worn. As is most clearly shown in FIGS. 2 and 3, the absorbentstructure 16 is provided with elastic ribbons 48 or strands affixedbetween the topsheet 20 and the backsheet 22. The elastic ribbons extendfrom an area in the rear end region 32 remote from the transverse edge36 along a path generally parallel to the longitudinal edges 34 of theabsorbent structure to an area in the front end region 28 remote fromits transverse edge 36. In the illustrated embodiment, three elasticribbons 48 or strands are shown for each leg cuff. The person skilled inthe art will, however, appreciate that the actual number of elasticribbons may be varied, as may their size. Thus, although the ribbons areillustrated as threads, it will be appreciated that strips of elasticmaterial may be used instead.

[0067] Each belt half 12, 14 is attached to the absorbent structure 16at the rear end region 32 of the rear panel 30 by a respective joint,generally denoted by reference numeral 50. One example of a joint 50which may be used in the absorbent article of the present invention isillustrated in FIG. 3. It is to be understood that, although the jointwill be described below only with reference to one belt half 14, anidentical joint may be used for the other belt half 12. A length 52 ofthe belt half 14 is attached to the absorbent structure 16 at the rearend region 32 between the topsheet 20 and the backsheet 22. The length52 of the belt half thus sandwiched between the topsheet and backsheetwill vary depending on the size of the absorbent article, but istypically between 8 and 10 cm. When, and in what order, the belt half isattached to the topsheet and backsheet will depend on the chosenmanufacturing process. The belt half 14 is generally spaced a shortdistance, for example about 1 cm, from the transverse edge 36 of theabsorbent structure and, prior to being worn, the longitudinal axis 42of the belt half may extend substantially parallel to the transverseedge. Thus, in the illustrated embodiment, the longitudinal axis of thebelt half extends parallel to the transverse axis T of the absorbentstructure. The joint 50 between the belt half 14 and the rear end region32 comprises two spaced substantially parallel lines of attachment 54between the belt half and the backsheet 22. The line of attachment 54adjacent the longitudinal edge 34 of the absorbent structure 16 may bespaced a short distance from the longitudinal edge. This line ofattachment is generally narrower than the line of attachment remote fromthe longitudinal edge 34 of the absorbent structure. The two spacedlines of attachment 54 generally extend from the transverse edge 36 ofthe rear end region parallel to the longitudinal axis 18 of theabsorbent structure across the entire width of the belt half andslightly beyond. Although the lines are shown to be continuous, it is tobe understood that they may instead comprise intermittent lines ofattachment. Preferably, the lines of attachment 54 are adhesive bondlines, though any attachment methods, such as thermal or ultrasonicbonding, may be employed.

[0068] The two spaced substantially parallel lines of attachment 54 atleast partially delimit a non-attached longitudinally extending region56 between the belt half 14 and the backsheet 22. This non-attachedregion 56 permits the elastic ribbons 48 or strands of the elasticisedleg cuffs to snap back during manufacture. Thus, free ends of theelastic ribbons 48 or strands reside in the non-attached longitudinallyextending region 56. To firmly anchor the elastic ribbons 48 within theabsorbent structure 16, the joint 50 between the belt half 14 and therear end region 32 further comprises a region 58 of attachment betweenthe backsheet 22 and the belt half. The region 58 of attachment extendsbetween the two spaced substantially parallel lines of attachment 54over the elastic ribbons 48. Advantageously, the region 58 of attachmentextends in the longitudinal direction beyond the point at which the twospaced parallel lines of attachment 54 terminate. The joint 50 betweenthe belt half 14 and the rear end region 32 may further comprise atleast one region of bonding between the belt half and the topsheet 20.Such region may comprise substantially the entire surface of the belthalf which lies adjacent the topsheet 20. This region of bonding may besuitably achieved by spray bonding the topsheet to the belt half.

[0069] In accordance with the present invention, the joint 50 isdesigned to meet certain minimum requirements. The present inventorshave discovered that, for the absorbent article to functionsatisfactorily, the joint 50 should be capable of withstanding a certaintension force applied to the belt halves at a certain angle a to thetransverse axis of the absorbent structure for a certain minimum periodof time. Thus, and in a manner which will be explained in greater detailbelow, the joint is subjected to a test procedure such that, and asillustrated in FIG. 4, a portion of the absorbent structure 16 issecured to a test rig, generally denoted reference numeral 60, and aload of 35 N is applied to the belt half 14 while the belt half externalof the absorbent structure 16 is maintained at a predetermined angle ato the transverse axis of the absorbent structure. The time up tofailure of the joint, i.e. when the belt half completely dissociatesfrom the absorbent structure, is measured. The time to failure ishereinafter referred to as the release time of the joint. In accordancewith the present invention, the minimum average release times of thejoint should be:

[0070] when α=10°, t>>720 seconds;

[0071] when α=20°, t>>330 seconds;

[0072] when α=25°, t >22 240 seconds;

[0073] when α=30°, t>>180 seconds; and

[0074] when α=40°, t>>75 seconds.

[0075] In a preferred embodiment of the invention, the following minimumaverage release times (t) of each belt half from the absorbent structureare attained:

[0076] when α=10°, t>>740 seconds;

[0077] when α=20°, t>>340 seconds;

[0078] when α=25°, t>>245 seconds;

[0079] when α=30°, t>>190 seconds; and

[0080] when α=40°, t>>80 seconds.

[0081] In a more preferred embodiment of the invention, the followingminimum average release times (t) of each belt half from the absorbentstructure are attained:

[0082] when α=10°, t>>760 seconds;

[0083] when α=20°, t>>350 seconds;

[0084] when α=25°, t>>250 seconds;

[0085] when α=30°, t>>200 seconds; and

[0086] when α=40°, t>>85 seconds.

[0087] In a further embodiment of the invention, the following minimumaverage release times (t) of each belt half from the absorbent structureare attained:

[0088] when α=10°, t>>780 seconds;

[0089] when α=20°, t>>360 seconds;

[0090] when α=25°, t>>255 seconds;

[0091] when α=30°, t>>210 seconds; and

[0092] when α=40°, t>>90 seconds.

[0093] In accordance with a most preferred embodiment of the invention,the following minimum average release times (t) of each belt half fromthe absorbent structure are attained:

[0094] when α=10°, t>>800 seconds;

[0095] when α=20°, t>>370 seconds;

[0096] when α=25°, t>>260 seconds;

[0097] when α=30°, t>>220 seconds; and

[0098] when α=40°, t>>100 seconds.

[0099] The minimum average release times are established in thefollowing manner.

[0100] With reference to FIG. 5, a section of the rear panel 30including the joint 50 is cut out from the absorbent structure 16. Afirst cut line 62 is made parallel to the longitudinal axis 18 of theabsorbent article at least 45 mm from the end edge of the belt half 14nearest the longitudinal axis 18. The first cut line 62 extends beyondthe lower edge, i.e. the edge nearest the transverse axis T of theabsorbent article, of the belt half 14 by at least 45 mm. The first cutline intersects a second cut line 64 extending parallel to thetransverse axis T of the absorbent article at least 45 mm from the loweredge of the belt half 14. The thus cut out section of the absorbentstructure 16 including the joint 50 is then clamped in the test rig 60which will be described in greater detail in the following.

[0101] With reference to FIG. 6, the test rig 60 comprises a rectangularbase plate 66 to which a rotatable plate 68 is mounted. A pair of clamps70 spaced at 90° to each other are mounted on the rotatable plate 68.With reference to FIG. 4, the rotatable plate 68 can be rotated withrespect to the rectangular base plate 66 such that suitable values ofthe angle a are obtainable. The test rig 60 is provided with lockingmeans to enable the rotatable plate to be locked at angular positions atwhich desired values of a are obtained. The rectangular base plate 66may be provided with holes 72 to enable the base plate to be maintainedin a vertical position on a frame (not shown) or the like.

[0102] Dimensions and constructional details of the test rig 60 will beapparent from the attached FIGS. 7 to 14.

[0103] The method for establishing the minimum average release times isthe following.

[0104] Sections are cut out from fifty identical absorbent articles. Inorder to avoid the influence of aging of the articles on the testresults, the articles should be no more than 6 months old, i.e., thetest is to be performed on articles which have been manufactured duringthe past six months. The cut out section of a first absorbent structure16 is secured by the clamps 70 to the test rig 60, as shown in FIG. 4.The orientation of the cut out section must be such that the clamps 70clamp the cut out section along lines parallel to the transverse axis Tand the longitudinal axis 18 of the absorbent article. In FIG. 4, theedges of the belt half 14 within the absorbent structure 16 are parallelto the transverse and longitudinal axes respectively. Thus, these edgesare parallel to, and spaced from the clamps 70. In order to ensure thatthe clamps do not contact the belt half 14, a spacing of about 1 cm maybe employed. The rectangular base plate 66 is held vertically and therotatable plate 68 is rotated until an angle a of 10° is attained. Therotatable plate is locked at this position and a weight is clamped tothe free end of the belt half 14. The weight is slowly released until itapplies a tension to the belt half. The weight is then allowed to hangfreely. The weight and clamp together apply a force of 35 N to the belthalf. As soon as the weight is allowed to hang freely, a stop watch isstarted. As soon as the belt half completely dissociates from theabsorbent structure, i.e., when the weight hits the floor, the stopwatch is stopped and the elapsed time is noted.

[0105] The above procedure is repeated for nine further cut out sectionsat α=10°.

[0106] For the next ten cut out sections, the above procedure isrepeated for α=20°.

[0107] Batches of ten cut out sections are then subjected to the aboveprocedure, but for α=25°, 30° and 40°.

EXAMPLE

[0108] The above procedure was conducted on a belted absorbent articleto ensure that its joint 50 between each belt half and the absorbentstructure is sufficiently strong. The following results were obtained(note that the elapsed time is given in minutes and seconds): a = 10°20° 25° 30° 40° Sample 1 12:31 05:35 03:21 04:23 01:49  2 10:16 05:4205:51 04:14 01:52  3 12:52 06:27 04:41 03:25 01:25  4 13:34 07:10 03:3702:58 01:17  5 11:05 05:43 04:28 02:59 01:45  6 11:45 05:21 04:01 03:2900:52  7 16:24 07:11 03:59 02:18 01:25  8 12:07 05:00 04:39 02:39 01:09 9 11:27 04:57 03:27 03:36 00:46 10 11:34 04:15 03:28 03:36 01:19Average: 12:21 05:44 04:09 03:21 01:21 St. dev. .01:41  00:57 00:4600:39 00:22 Min 10:16 04:15 03:21 02:18 00:46 Max 16:24 07:11 05:5104:23 01:52

[0109] Thus, the average release times for the joint of the EXAMPLE are:

[0110] when α=10°, t>>741 seconds;

[0111] when α=20°, t>>344 seconds;

[0112] when α=25°, t>>249 seconds;

[0113] when α=30°, t>>201 seconds; and

[0114] when α=40°, t>>81 seconds.

[0115] The above EXAMPLE relates to a belted absorbent article in whichthe belt halves are substantially rectilinear, i.e., the upper and lowerlongitudinal edges of the belt halves are substantially parallel to thesecond longitudinal axis 42. Thus, the angle a may be determined eitherby measuring the angle as shown in FIG. 4, or by measuring the anglesubtended by the second longitudinal axis 42. In cases in which the belthalves are non-rectilinear, i.e., the belt halves are curved, the anglea is determined by hanging the load of 35 N from the remote end of thebelt half such that the load acts along the longitudinal axis of thebelt half and determining the mid-point of the belt half between itsupper and lower longitudinal edges at the joint 50. A vertical line willthus be attained between the mid point and the load. The angle that thisvertical line subtends to the transverse axis T of the absorbent articlecorresponds to the angle α.

[0116] The invention is not restricted to the embodiments describedabove and shown in the drawings, but may be varied within the scope ofthe appended claims. For example, the topsheet 20 of the absorbentstructure 16 may be provided with so-called standing gathers to assistin retaining bodily wastes within the confines of the absorbentstructure.

What is claimed is:
 1. A belted absorbent article comprising: anabsorbent structure extending about a first longitudinal axis, saidabsorbent structure including a topsheet, a backsheet and an absorbentbatt disposed between said topsheet and said backsheet, said absorbentstructure having a transverse axis dividing the absorbent structure intoa front panel terminating in a front end region and a rear panelterminating in a rear end region, said absorbent structure beingdelimited by opposed longitudinal edges and opposed transverse edges,and a pair of opposed belt halves attached to said absorbent structureat said rear end region of said rear panel, each of said belt halvesbeing attached by a respective joint, each belt half extending about alongitudinal axis of the belt such that each belt half extends outwardlyfrom a respective longitudinal edge of the absorbent structure, whereineach of said joints between each said belt half and said absorbentstructure is designed such that when each said belt half is subjected toa tension force of 35 N acting along said longitudinal axis of the beltand said longitudinal axis of the belt creates an angle (α) to saidtransverse axis of said absorbent structure, the following minimumaverage release times (t) of each said belt half from said absorbentstructure are attained: when α=10°, t>>720 seconds; when α=20°, t>>330seconds; when α=25°, t>>240 seconds; when α=30°, t>>180 seconds; andwhen α=40°, t>>75 seconds.
 2. The article as claimed in claim 1, whereinthe following minimum average release times (t) of each said belt halffrom said absorbent structure are attained: when α=10°, t>>740 seconds;when α=20°, t>>340 seconds; when α=25°, t>>245 seconds; when α=30°,t>>190 seconds; and when α=40°, t>>80 seconds.
 3. The article as claimedin claim 1, wherein the following minimum average release times (t) ofeach said belt half from said absorbent structure are attained: whenα=10°, t>>760 seconds; when α=20°, t>>350 seconds; when α=25°, t>>350seconds; when α=30°, t>>200 seconds; and when α=40°, t>>85 seconds. 4.The article as claimed in claim 1, wherein the following minimum averagerelease times (t) of each said belt half from said absorbent structureare attained: when α=10°, t>>780 seconds; when α=20°, t>>360 seconds;when α=25°, t>>255 seconds; when α=30°, t>>210 seconds; and when α=40°,t>>90 seconds.
 5. The article as claimed in claim 1, wherein thefollowing minimum average release times (t) of each said belt half fromsaid absorbent structure are attained: when α=10°, t>>800 seconds; whenα=20°, t>>370 seconds; when α=25°, t>>260 seconds; when α=30°, t>>220seconds; and when α=40°, t>>100 seconds.
 6. The article as claimed inclaim 1, wherein each said belt half is attached to said absorbentstructure at said rear end region between said topsheet and saidbacksheet.
 7. The article as claimed in claim 6, wherein each of saidjoints between each said belt half and said rear end region comprisestwo spaced substantially parallel lines of attachment between each saidbelt half and said backsheet.
 8. The article as claimed in claim 7,wherein said two spaced substantially parallel lines of attachment areadhesive bond lines.
 9. The article as claimed in claim 8, wherein saidtwo spaced substantially parallel lines of attachment at least partiallydelimit a non-attached longitudinally extending region between each saidbelt half and said backsheet within which region ends of elastic ribbonsforming elasticised leg cuffs reside.
 10. The article as claimed inclaim 9, wherein each of said joints between each said belt half andsaid rear end region further comprises a region of attachment betweensaid backsheet and each said belt half, said region of attachmentextending between said two spaced substantially parallel lines ofattachment over said elastic ribbons.
 11. The article as claimed inclaim 10, wherein each of said joints between each said belt half andsaid rear end region further comprises at least one region of bondingbetween each said belt half and said topsheet.